But an error during knitting can mean a half-completed TeX document and serious trouble later in the toolchain. And errors do happen -- I rerun my scripts *a few* times before they are error-free, and this includes the occasional typo in an inline expression.

A document with errors in inline expression is not yet production quality anyway, but really, please, don't abort knitting just because of that :-)

Do we have concordance information for inline expressions? Then it's really easy to print a file:lineno style error summary.